Monitor Audio Gold GX 5.1 Speaker System Review

If you have an exceptional memory, you might recall reading about the Monitor Audio Gold GX series speakers in these pages before. I reviewed the GX200 floor standing loudspeakers ($4,995/pair) from this series back in the October/November 2011 issue. The GX200 proved itself as a very capable speaker in my two channel system and offered many of the sonic characteristics that I was fond of. In fact I took enough liking to these speakers that I ended up buying them after the review. Since I wasn’t looking to make any changes in my two channel system, the GX200s became a part of the upgrade path for my basement home theatre system. Of course a pair of loudspeakers at the front of the room hardly makes a home theatre system, so I asked Canadian distributor Kevro International to send us the remaining speakers to make a full 5.1 system. The complete system to be evaluated in this review includes the GXC150 centre channel ($1,195), a pair of the GX-FX surround speakers ($2,390/pair) and the GXW15 subwoofer ($3,195). The total price of this 5.1 system rings in at $11,775. At this price my expectations were set pretty high, as they should be.

The Gold GX series sits just below Monitor Audio’s flagship Platinum series. As you might expect, much of the technology in the Gold GX series is derived from lessons learned during the development of the Platinum series. Aside from all the technology, the surround speakers and the subwoofer offer some features rarely found in speakers. Visually, each of the models in the Gold GX series is quite attractive and a good selection of finishes means that they’ll integrate comfortably with just about any room décor. Available finishes include Bubinga, Dark Walnut, as well as glossy Piano Ebony, White and Black. There really is a lot to get excited about here. Let’s examine each of the models in this review a little closer and you’ll see what I mean.

The GX200 floorstanding speaker is the little brother to the GX300. Its three-way design sports a C-CAM (Ceramic-Coated Aluminium/Magnesium) high frequency ribbon transducer, a 4 inch RST mid-range driver and two 5.5 inch RST bass drivers. All of the drivers in this speaker use Monitor Audio’s C-CAM technology, a material originally developed by the aerospace industry for jet engine components. The C-CAM manufacturing process combines the various materials through a series of specific steps which result in an alloy cone that is very light, yet extremely rigid. This makes the C-CAM drivers much less susceptible to flexing or twisting during operation compared to other cone designs and results in a significantly reduced distortion.

The proprietary ribbon transducer is an ultra-thin sandwich of the C-CAM alloy suspended in a transverse magnetic field of high energy rare earth magnets. Thanks to its mass of just 18 mg, its diaphragm is extremely quick at starting and stopping and hence is capable of reproducing the leading edges of notes and musical details unlike the more typical tweeter dome designs. The ribbon transducer is capable of achieving frequencies above 60 kHz and while this is beyond the threshold of human hearing, it means that you’ll be able to hear all the musical nuances and harmonics found in high resolution audio content.

What makes the 4 inch RST (Rigid Surface Technology) mid-bass driver special are a series of radial ribs which significantly increase cone rigidity compared to other cone designs. Increased rigidity translates into a lower distortion, while the use of the light weight C-CAM cone means higher speed and accuracy. The 5.5 inch RST bass drivers use the same technology as the 4 inch RST driver but offer a larger driver size and heavier construction with bigger magnets.

The GX200 has a frequency response rated from 35 Hz to 60 kHz, a sensitivity of 89 dB and an impedance of 8 ohms. The GXC150 centre channel offers a 2.5-way, sealed cabinet design, housing two of the same 5.5 inch RST drivers as the GX200, with the same ribbon transducer in between them. Its frequency response is rated from 55 Hz to 60 kHz, while its sensitivity and impedance matches the floorstanding model.

The GX-FX is far from an ordinary surround speaker. It can provide either direct (monopole) or ambient surround (dipole) sound with just a flick of a switch on the speaker itself or with a 12 volt trigger from the AV receiver. This makes it one of the most versatile surround speakers on the market today suitable for use in just about any room environment. In the monopole mode, the GX-FX uses its front-firing 6.5 inch RST driver and a ribbon transducer to produce sound. In the dipole mode, it uses two pairs of side-firing 4 inch C-CAM drivers and 1 inch C-CAM gold-dome tweeters, together with the front-firing 6.5 inch RST driver. The dipole arrangement produces a more diffuse, enveloping sound. The GX-FX speakers are designed to be stand mounted (a matching stand retails for $595) or can be installed flat on the wall with the included brackets. Specifications of the GX-FX include a frequency response of 60 Hz to 60 kHz, a sensitivity of 87 dB and an impedance of 8 ohms.

All of the GX series cabinets are constructed out of 20 mm MDF, while each offers its own bracing to improve rigidity and minimize cabinet colouration. Each speaker in this series offers bi-wire terminals with factory installed spade jumper cables.
Rounding out the GX series is just a single subwoofer called the GXW-15, and like the GX-FX surround speakers this is not just another run of the mill subwoofer. Its sealed enclosure is equipped with an ultra-long throw 15 inch C-CAM bass driver, capable of a whopping 1.5 inches of excursion. For a 15 inch subwoofer it has an attractively small enclosure, measuring roughly 16 inches in each of the three dimensions. Its power comes from a 650 watt (1,200 watt peak) D2AudioTM DSP controlled, Class-D amplifier. The rear connection panel offers both RCA and LFE inputs and outputs. What makes the GXW-15 stand apart from the crowd is an on-board advanced automatic room correction system called LEO (Listening Environment Optimizer) by D2Audio. The GXW-15 has a frequency response rated down to an earth shattering 18 Hz. Unlike the typical subwoofer the GXW-15 has a small display at the top of its baffle as well as a knob/button just above it, which in theory you never have to use because all functions can be controlled from the supplied remote controller. ‘nuff said.

The subwoofer manual says to run the LEO system before running that AV receiver auto calibration so that’s exactly what I did. Running LEO is a minimalist affair – plug in the supplied microphone, place it where you would normally sit and let the system run its course of test tones. The whole thing took only a couple of minutes in total. Following this, I ran the auto calibration of my Pioneer Elite SC-07 AV receiver. And now it was time for the fun stuff! I should mention that part way through this review process I switched to a much higher performance Arcam FMJ AVR600 AV receiver.

Armed with a stack of Blu-ray discs, both music and movies, and SACDs I fired up my recently purchased Cambridge Audio Azur 751BD universal blu-ray player and grabbed a seat on the couch. Yes, a reviewer’s life can be a tough gig sometimes.

First up was the Rolling Stones Shine a Light concert Blu-ray, Martin Scorsese’s take on what a Stones concert disc should look like. The track “As Tears Go By” opens with Keith Richards playing an amazing 12 string acoustic guitar lick and I’ve honestly never heard it sound this good on any home theatre system. The Monitor Audio speakers delivered the richness of the doubled-up guitar strings with fullness in the mid frequencies and an amazing bell-like quality in the higher octaves. The depth and texture of this presentation was as close as I’ve heard from a real 12 string guitar. When Richards strummed full chords, the strings rang in a perfect union, yet at the same time I could hear the distinct sound of each string. The ribbon tweeters reproduced the high frequencies of both instruments and voices with an amazing sizzle and a high level of detail. The tweeter presentation was airy, super clean and smoothly integrated with the mid frequencies, not once did I detect any harshness in the upper registers. I also never got tired even during long listening sessions. Ribbon tweeters offer a wider horizontal dispersion compared to dome tweeters and hence offer a larger horizontal sweet spot. It should however be noted that ribbon tweeters have a limited vertical dispersion and as a result sound best when your ears are at their level. Further enhancing the performance of this song, the surround speakers did a great job of providing the ambience as the crowd sang along during the chorus. The Monitor Audio speakers provided me with plenty of listening pleasure as I enjoyed the rest of the tracks on this disc.

Next I switched to the Dire Straits: Brothers In Arms SACD, a fantastic album (on many different levels) that gets plenty of play time in both my two and multi-channel systems. The Gold GX series served up a perfectly balanced frequency range and one of the cleanest, luscious sounding mid-ranges I’ve had the pleasure of listening to in my home theatre. The ribbon tweeters extracted the finest musical details with the outmost delicacy. Tracks like “So Far Away” and “Money For Nothing” presented me with a holographic soundstage – which reached well beyond the walls of my listening room as drums played all around my listening seat. Meanwhile, the GXW-15 subwoofer blended smoothly with the rest of the speakers and provided perfectly resolved and well articulated bottom frequencies.

Flute Mystery (by Fred Jonny Berg) on Blu-ray gave me the chance to listen to a wide variety of string and air instruments. The reproduction of this DTS-HD Master soundtrack was superb, every instrument sounded rich and tonally accurate. I decided to take this opportunity to investigate the difference with the GX-FX surround speakers operating in monopole mode versus the dipole mode. The monopole mode, recommended when the GX-FX is used as a rear speaker in a 5.1 system, produced a direct yet incredibly smooth sound and reproduced all of the fine intricacies of the music. Not surprisingly the dipole mode, recommended when the GX-FX is used as a side or rear speaker in a 7.1 system, produced a much subtler surround effect. Rather than sending the sound directly to my ears most of it was sent to the side drivers. As a result the surround channels produced a much gentler sound – I was hearing more of an ambient sound rather than the full character of the instruments as in the monopole mode. Both modes worked wonderfully well but I stuck to the recommended monopole setting for most of my listening.

While there was nothing wrong with having the Pioneer Elite SC-07 AV receiver driving these speakers, I knew that a higher level AV receiver, like the Arcam FMJ AVR600, should bring a further improvement to what I was hearing. After all, the Gold GX isn’t just another speaker series – this is Monitor Audio’s second series from the top and should be capable of more than the Pioneer receiver can send its way. It didn’t take very long to realize that with the Arcam in place the sonic improvement was remarkable. The audio became more organic and further refined, particularly noticeable with voices and instruments. There was also a noticeable improvement in clarity and detail extraction. Yes, this was a greater pairing for certain. Hence, I conducted the remainder of the review with the Arcam.

If you’d like to read my impressions about the sound of the GX 200 floor standing speakers in a 2-channel system, I invite you to read my review in the October/November 2011 issue (now available on www.canadahifi.com/).

Having established the excellent music performance of the Gold GX speaker, in both two and multichannel tests, I set out to evaluate their sound as a companion for movies. I began with Star Trek VI: The Undiscovered Country on Blu-ray. The Dolby TrueHD soundtrack sounded great from the outset. The mesmerizing orchestral performance during the opening credits started off softly and gradually built in intensity and dynamics. The Gold GX speakers did a very good job of reproducing all of the various sections of the orchestra. I was enveloped by sound emitted from all around me, from a perfectly blended surround mix. The crisp, highly detailed presentation of the Gold GX speakers offered much of the character that one would expect from a good hifi speaker. The subwoofer had its first chance to strut its stuff at the very beginning of the first scene as a large cosmic explosion swept across the soundstage from the front to the back of the room. The bass was presented with great depth and tightness, not just by the subwoofer but also by the surround speakers. During the first few minutes of the film I noticed that the Gold GX had a slight advantage over other speaker designs thanks to their ribbon tweeters. This advantage was the clarity of the dialogue. Unlike with some of the other speakers I’ve listened to in the past, the GX centre channel never failed to deliver a clean rendition of the character voices – regardless of how many other layers of sound were in the mix. Another advantage was that the dialogue was clearly audible even at very low volume levels.

While watching Thor on Blu-ray, what I got was a decidedly cinematic experience. The Gold GX speakers handled this incredibly dynamic soundtrack with the outmost control. Sound during quieter scenes was delivered with delicacy and precision. Low frequencies during loud scenes were capable of delivering seismic thumps but always sounded tight and controlled. The LEO automatic room correction system built into GXW15 subwoofer did a phenomenal job of smoothing out the bass frequencies in my room, and provided a better bass response in all the seats on my couch. Dialogue was always super clean, even when layered with other sounds and effects. Again I noticed that voices were very clear even at lower volume levels. In one of the scenes, as Thor snuck into the Shield agency site set up to investigate the “satellite” crash site, all of the speakers worked in unison to create fantastically realistic rainfall and thunderstorm.

The Monitor Audio Gold GX series offered a stellar performance in my home theatre and for a total price of just under $12,000 for a 5.1 system you would certainly expect them to. Whether I listened to music or watched movies, they never failed to engage me at the highest level. Voices and instruments sounded true-to-life and hence music was always full of emotion, regardless of genre. On many occasions I felt like the performers were right in my room. During movies with good soundtracks (and visuals) the Gold GX series were capable of creating a total suspension of disbelief, making me feel like I was part of the action. Yes it is possible to assemble a home theatre speaker system for a much smaller amount but you’ll miss out on all the dynamics, details and realism that only a higher-end speaker system like the Monitor Audio Gold GX can deliver.